The increasing concerns over chemical pesticide residues, pest resistance, and environmental degradation have accelerated the search for effective botanical alternatives in stored product pest management. This study investigates the comparative bio-control potency of three widely available plant-based extracts—Neem (Azadirachta indica A. Juss), Garlic (Allium sativum L.), and Tobacco (Nicotiana tabacum L.)—against common storage insect pests, with a focus on bean weevil (Acanthoscelides obtectus) and cowpea bruchid (Callosobruchus maculatus).

Crude extracts of neem seeds and leaves, garlic cloves, and dried tobacco leaves were prepared using water and ethanol as solvents. The treatments were applied to infested grains under laboratory conditions, and adult insect mortality, oviposition suppression, and grain damage levels were assessed over a 14-day period. Results showed that neem extracts exhibited the highest adult mortality rates, followed by garlic and then tobacco. Neem also significantly reduced egg-laying and grain damage, owing to the presence of azadirachtin and other limonoids. Garlic extract demonstrated moderate insecticidal activity, likely due to sulfur-containing compounds such as allicin, while tobacco showed a delayed mortality effect attributed to its nicotine content.